1. Technical Field of the Invention
The present invention relates to a process and a device for enabling a plurality of cigar wrappers to be cut out simultaneously from a leaf or half-leaf of tobacco.
2. Discussion of the Prior Art
Processes for simultaneously cutting out from a given surface a plurality of elements having identical predetermined contours are already known from the prior art and are widely used at present. The means used are generally mechanical means shaped to have the same profile as that of the elements to be cut out. They may also be more precise means, but also more delicate ones, such as the water jets or lasers. However, in any case, the technical problem to be solved is relatively simple, as the surface from which the elements are to be cut out may be used entirely. Therefore there is no need to modify the plane of cut from one simultaneous cut-out to the following simultaneous cut-out.
The problem is much more complex in the field of tobacco where the surfaces to be cut out are plant leaves, none of which resembles another: they differ not only by their size and outer shape, but also by the position of the ribs and possible defects, the quality of the parenchyma, etc. It is therefore obvious that, from one leaf to another, and even from one half-leaf to the other half of the same leaf, the possible number and arrangement of wrappers to be cut out differs. A new plane of cut must therefore be provided and adjusted as a function of the particularities of each half-leaf.
In response to this technical problem, mechanical means have already been used where the cut-out tools have the same profile as that of the wrappers to be cut out. To obtain a simultaneous cut-out of a plurality of wrappers from a half-leaf, it has sufficed, after the cut-out tools were subjected to a new arrangement in spaced adapted to the geography of the half-leaf, to place the tools in contact with the half-leaf, or place the half-leaf in contact with the tools.
However, the technical problem has not yet been solved if another type of cut-out tool is used: e.g., tools such as water jets or lasers which must exactly follow the profile of the wrappers to be cut out.
In the case of such tools, it could well be imagined to actuate each separately.
This modus operandi is very simple; however, its realisation would lead to an unnecessarily complex and uneconomical device, as it does not take into account the fact that the contour of the wrappers to be cut out simultaneously are identical.
Another aspect of the problem resides in the necessity of coordinating the different operations, both in space and in time. The coordination in time implies that, for all of the wrappers cut from a leaf or a half-leaf, the cutting process must begin at the same time and end at the same time, without any time lag.
The coordination in space is also necessary, as two tools which cut out two wrappers tangential to each other must avoid obstructing each other.